Orienting device for borehole deflecting tools



Nov. 30, 1937. A. G. WELIKANOV ORIENTING DEVICE FOR BOREHOLE DEFLECTINGTOOLS Filed June 12, 1937 FIG. I

FIG 4.

/nvenfor: Alexander 6. We/ikanav By his AHQrneg-LgQ mtQE.

Patented Nov. 3%, E93? ORENTENG DEVICE FOR BOREHOLE DE Alexander G.

FLECTING TOOLS Welikanov, San Francisco, Calii'.,

assignor to Shell Development Company, San Francisco, Calif acorporation oi Delaware Application June 12, 1937, Serial No. 147,904 5Claims. (on. 255-4) The present invention pertains to the art ofdirectional drilling, and is more particularly concerned with animprovement in borehole deflecting tools of the universal orknuckle-joint type, whereby said tools may be properly oriented in aninclined borehole.

In drilling wells, it often happens that the direction in which aborehole is being drilled deviates from the vertical. In such cases itmay be desirable to change the direction of drilling either in order tobring the borehole back to the vertical, or "to deflect it in anotherdirection, or to increase the angle of deviation still further, as, forexample, in sea shore drilling, in drilling relief wells whileextinguishing well flres, etc.

Boreholes may be deflected in any desired direction by means of toolssuch as whipstocks, knuckle joint drillbits, etc. These tools, however,must be properly oriented in the borehole in order that the'latter maybe extended in. a desired direction. The orientation of whipstocks,knuckle joints, etc., is usually effected by means of methods involvingthe use of sighting devices, such' as described in the Anderson PatentNo. 1,770,224, or by means of orienting devices comprising magnetic -orgyroscopic compasses, box levels, etc., as described in the WillistonPatent No. 2,012,152.

These methods, however, have the disadvantage of involving aconsiderable, and sometimes unnecessary waste of time, since theorientation of deflecting tools does not necessarily have to be effectedwith regard to the points of the compass. Very often, it is onlyimportant to ascertain the position of thedeviation plane of theborehole, that is, of the vertical plane passing through the aids of thedeviating borehole with regard, for example, to the symmetry plane of awhipstock or of a knuckle joint. Any desired directional change indrilling may thereupon be effected by a suitableadjustment in the anglebetween said deviation plane and said symmetry plane. I

It is the object of the present invention to provide an improvement inknuckle joints, such, for example, as the Lewis knuckle joint describedin Patent No. 2,016,042, whereby said knuckle joint may m readily andpositively oriented with regard to the deviation plane of a borehole bymeans of a clinometer of Simple construction, such as a rolling ball oran acid bottle clinometer.

It is a further object of this invention to provide an improvement inknuckle joints, whereby the actual angle of fiexure of the muckle jointin a vertical plane can be positively determined.

These and other objects of the present invention will be betterunderstood from the following description, wherein:

Fig. 1 is cross-sectional elevation view of a knuckle-joint providedwith marking means for orienting said knuckle joint according to themethod of the present invention.

Fig. 2 is a plan view of the ball member of the knuckle joint.

Fig. 3 is an enlarged perspective view of said ball member.

Fig. 4 is a cross-sectional elevation view of a preferred type ofrolling ball clinometer used in orienting knuckle joints according tothe present invention.

Fig. 5 is an elevation view, partly in cross-section, of an acid bottleclinometer.

Referring to Fig. 1, which shows a conventional knuckle joint of theLewis type, the lower end of a drill string I is shown attachedto theupper portion 1 of the socket member of said knuckle joint. The lowerportion ll of this socket member is attached to said upper portion bymeans of screw threads t, and cooperates therewith in snugly and'securely enclosing and holding a ball member 85, forming thereby a balland socket universal joint. The ball member l5 forms the upper portionof a shaft 27, to the lower end of which a drill bit (not shown) of anydesired type' may be attached.

In order to transmit the rotation of the drill string to the drill bit,the ball member i5 is provided with vertical slots it in registry withpins is projecting inwardly through the socket memher.

In order that the drill bit shaft 21 may assume a desired fiexure anglewith the drill string, the axial bore through the lower socket member itis given a conical shape, as shown at t.

The universal joint is flexed, and shaft 2? is made to assume an angularposition with regard to the drill string by means of a cam collar l2,slidably mounted for longitudinal movement along the shaft 2?, and keyedagainst rotational movement with regard thereto by means of keys 2i. Theslidable cam collar 92 is normally urged upwards by a strong spiralspring 23 mounted around the shaft 21 and held in place by a nut 25..

The upper face of the cam collar 92 is raised on one side, as shown at8, whereby the pressure of the spring 23, tending to force the camcollar in contact with the lower edge of the socket member l'i, flexesthe universal joint and deflects the drill bit shaft 2? with regard tothe drill string, as shown in Fig. 1.

In order that the drilling fluid may be supplied to the bit, the socketmember 1 is provided with an axial bore 5 registering with the drillpipe. A similar bore l9 extends through the drill bit shaft 21 and theball member I5. In order that the flow of the fluid be not impeded whenthe universal joint is flexed and the bore through the socket member 1is partially thrown out of register with the bore l9 through the ballmember [5, the latter bore is enlarged at its upper end to form anupwardly opening funnel, as shown at 2.

A projecting marking member 9, is aflixed to the wall of the funnelopening, as shown in elevation on Fig. 1, in planview in Fig. 2, and inenlarged perspective View in Fig. 3. This member may be cast or machinedtogether with the ball member I5, or may be provided with flanges 2| andattached to the ball member by means of screws or bolts 22, as shown inFig. 3. The marking member has a sharp upper edge I 0, which may be cutto form a series of sharp tooth points. The sharp edge I0 is given adesired calibrated length,

such for example, that when the drill bit shaft 21 is deflected to itsextreme position, the outermost tooth point of the marker 9 is projectedto intersect the axial line of passage 5. The marking member 9 isaflixed in known relationship to the raised portion 3 of cam collar I2:for example, it may be placed in the plane passing through keys 2|, sothat sharp edge 10 lies in the symmetry or deflection plane of theknuckle joint and indicates the direction in which the latter is deflected. Owing to its relatively small size, and its preferablytriangular vertical cross-section, the marking member 9 offers noappreciable resistance to the flow of drilling fluid.

Fig. 4 illustrates a preferred type of clinometer used in orienting theknuckle joint described above.

This clinometer comprises a cylindrical casing 31, closed at the top bya cap 33, provided with an opening 3|, and at the bottom with a cap 43,having an axial bore 45. A piston 34 flts snugly inside the casing 31,and is provided on its upper face with a suitable attachment device 32,by means of which the clinometer may be lowered inside the drill pipeinto the borehole, at the end of a wire line or of a sucker rod string,during which operation the piston 34 is held in its uppermost positionby the lowering means. A second piston 39 is slidingly fitted within theclinometer, and is normally urged upwards by a spring 49 supported onthe lower cap 43. The upper end of a piston rod 42 is screwed into thepiston 39, while its lower end is screwed into a cylindrical member 41,the piston rod passing slidingly through the bore 45 in the lower cap43. A disc 35, made of lead or any other suitable deformable material isaffixed in known position to the upper face of piston 39, for example,by means of pins 33. A metallic ball 36 is placed within the clinometerbetween the pistons 34 and 39, and is free to roll therein under theaction of gravity, being preferably supported between the edge of thedisc 35 and the inside wall of the clinometer casing. The lower face ofpiston 34 may be provided, if desired, with a downwardly projectingcentral portion 34a. The distance between the lower face of thisprojection and the lead disc 35 is made smaller than the diselected sothat when it is fully expanded there isa certain clearance space betweenthe ball 39 and the upper piston 34.

The cylindrical member 41, which is attached to the piston rod 42, isadapted to enter the pas; sage 5 in the socket member I of the knucklejoint. It carries at its lower end a second lead disc 49, which isattached thereto by any suitable means, for example, by means ofcountersunk screws 44.

The lead discs 35 and 49 are aflixed to the oilnometer in knownrelationship to each other, and

, may carry identifying marks from which their angular position withregard to each other may be determined.

In order to determine the position of the symmetry or deflection planeof the knuckle joint tool with regard to the deviation plane of aninclined borehole, the following procedure is followed:

The knuckle joint is lowered into the borehole on the end of a, drillstring. The clinometer is then lowered inside the drill string, forexample, on the end of a wire line, which permits the operation to becarried out very quickly. The clinometer comes to rest on the seat 3,formed at the coupling of the last drill with the knuckle joint. Themember 41 enters the passage 5 in the socket member of the universaljoint, the disc 49 coming to within a small distance of the marker 9which projects into said passage due to the deflection of the ball andshaft member l5-21 under the action of spring 23 and cam collar 12.

A fluid under pressure may then be pumped through the drill string. Theflow of the fluid being stopped by the clinometer seated on seat 3, thepressure of the fluid acts to move the piston 34 downwards. The ball 36is caught between the lower face of piston and the deformable disc 35,the pressure applied being suillcient to produce an impression on thesoft material of the latter.

On further downward motion of piston 34, the pressure is transmitted,through ball 33 and,.if desired, through the downwardly projectingcentral portion' 34a of the piston 34, to the piston 39, which movesdownwards against the action of the spring 40. The piston rod 42 and themember-41 move together with piston 39, the disc 49 on the member 41coming into contact with the marker 9 and receiving an impression therefrom.

Since, as stated above, the marker 9 is afllxed to the funnel-shapedpassage opening of the ball member I5 in known angular relationship tothe cam collar l2, for example, in such manner that the sharp upper edgeID of the marker indicates the direction in which the bit of the knucklejoint is deflected, and since the ball '36 assumes by gravity thelowermost position within the c1inometer, the two marks on discs 35 and49 provide, on withdrawing the clinometer and correlating the two discs,positive means for ascertaining the angular relationship of the boreholedeviation plane to the knuckle joint symmetry plane, whereafter thisrelationship may be adjusted in any desired manner.

If, for some reason, such as jamming or an, insufficient diameter of thebottom hole, the knuckle joint is not deflected to the desired fullextent, the marker 9 will project only partially into the passage 5, andonly a few of the teeth of the sharp edge III will leave theirimpression on the disc 49. The exact angle at which the knuckle joint isdeflected, and therefore the angle at which hole enlarged with a bottomhole reamer to a desired diameter.

The desired impressions on discs 35 and 49 may also be obtained withoutapplying fluid pressure to the clinometer. For example, if theclinometer is lowered at the end of a sucker rod string, the weight ofsaid string when properly released at the top is sufficient to forcepistons 34 and 39 downwards and to obtain the desired indications.

It is understood that the construction of clinometer illustrated in Fig.4 is described here only by way of an example, and that the same resultsmay be achieved by the use of any other type. of clinometer capable ofindicating the deviation plane of an inclined borehole. For example, anacid bottle'clinometer, shown in Fig. 5, may be lowered into theborehole at the end of a sucker rod string 50. It comprises a casing anda lower member 51 similar to that of the clinometer of Fig. 4. Themember 51 is made slightly longer than the member 41 of the rolling ballclinometer, so that the lead disc 59 is forced into contact with themarker 9 at the moment when the acid bottle clinometer comes to rest onseat 3. The clinometer of Fig. contains a properly cushioned acid bottle55. Due to the inclination of the borehole, the acid etches, in wellknown manner, an elliptical line on the glass of the bottle. Since themajor axis of this ellipse lies in the deviation plane of the well, thecoordinated indications of the acid bottle 55 and of the disc 59 providemeans for determining the angular relationship between the deviationplane of the borehole and the symmetry plane of the knuckle joint, andthe desired adjustment between these two planes may be effected asdescribed.

I claim as my invention:

1. In a method for orienting in an inclined borehole a deflectingdrilling tool comprising a universal joint provided with marking meansindicating the deflection plane of said joint, the steps of loweringsaid tool in a flexed position into a borehole on a drill string,lowering into the drill string a clinometer capable of indicating thedeviation plane of the borehole and adapted to receive an impressionfrom the marking means on the universal joint when said joint is flexed,and recording the angular displacement in a horizontal plane of thedeviation plane of the borehole with the deflection plane of theuniversal joint.

2. In a method for orienting in an inclined borehole a deflectingdrilling tool comprising a universal joint provided with marking meansindicating the deflection plane of said joint and the extent of itsflexure, the steps of lowering said tool in a flexed position into aborehole on a drill string, lowering into the drill string a clinometercapable of indicating the deviation plane of the borehole and adapted toreceive an impression from the marking means on the universal joint whensaid joint is flexed, and recording the angular displacement in ahorizontal plane of the deviation plane of the borehole with thedeflection plane of the universal joint, and the extent of flexure in avertical plane of said joint.

3. In a deflecting drilling tool adapted to be lowered into a boreholeon a drill pipe string, a

flection plane of the universal joint and actuated by the flexure of theuniversal joint into operative position within said bore, and aremovable clinometer adapted to be lowered through the drill pipe and torecord the deviation plane of the borehole, said clinometer beingprovided with deformable means adapted to come in contact and to receivean impression from the marking means when said marking means are inoperative position.

4. In a deflecting drilling tool adapted to be lowered into a boreholeon a drill pipe string, a socket member attached to the drill pipe, aball member held within the socket member and forming therewith auniversal joint, a shaft member attached to the ball member, means todeflect the ball and shaft members with regard to the socket member, abore through the socket, ball and shaft members co-axial with the passage through the drill pipe, marking means affixed to the ball member andadapted to project within the passage through the socket member when theuniversal joint is flexed, a removable clinometer adapted to be loweredthrough the drill string and to record the deviation plane of theborehole, said clinometer being provided with deformable means adaptedto enter the borethrough the socket member and to receive an impressionfrom the marking means on the ball member when the ball and shaftmembers of the universal joint are deflected with regard to the socketmember.

.5. In combination with a deflecting drilling tool attached to a drillpipe and comprising a universal joint, a bore through said jointco-axial with the passage through the drill pipe, and marking meansindicating the deflection plane of the universal joint and actuatedint'o operative position within said bore by the flexure of theuniversal joint, a removable clinometer adapted to be lowered into thedrill pipe, comprising gravity responsive means and deformable meanscooperating therewith for recording the deviation plane of the borehole,deformable means cooperating with the marking means of the universaljoint for recording the deflection plane of the universal joint, andpressure responsive means actuating said first and second deformablemeans into contact with said gravity responsive means and saidoperatively positioned marking means to record the relative angularposition of the deviation plane and of the deflection plane.

ALEXANDER G. WELIKANOV.

